Most of the GNU Emacs text editor is written in the programming
language called Emacs Lisp. You can write new code in Emacs Lisp and
install it as an extension to the editor. However, Emacs Lisp is more
than a mere "extension language"; it is a full computer programming
language in its own right. You can use it as you would any other
programming language.

Because Emacs Lisp is designed for use in an editor, it has special
features for scanning and parsing text as well as features for handling
files, buffers, displays, subprocesses, and so on. Emacs Lisp is
closely integrated with the editing facilities; thus, editing commands
are functions that can also conveniently be called from Lisp programs,
and parameters for customization are ordinary Lisp variables.

This manual describes Emacs Lisp, presuming considerable familiarity
with the use of Emacs for editing. (See `The GNU Emacs Manual' for
this basic information.) Generally speaking, the earlier chapters
describe features of Emacs Lisp that have counterparts in many
programming languages, and later chapters describe features that are
peculiar to Emacs Lisp or relate specifically to editing.

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